WHERE IN THE WORLD?
Polygonal patterns in
Arctic permafrost range
up to ten feet wide.
Ice blocks wedged in
the cracks are often
hundreds of years old.
Cold Canvas With no soft, green cover, blunt cuts made
by water and ice are visible on a delta beside the Rollrock River
on Ellesmere Island in the Canadian High Arctic. In this frigid, arid
landscape, cycles of freezing and thawing tear soil and stone into
weird and wild patterns known as stripes, sorted circles, and pingos
(an Inuit term used for earth-covered ice hills). The ice-wedge
polygons pictured above begin forming when severe cold cracks
the soil. In spring, water sluices into the cracks. Winter then freezes
the water into ice wedges that drive the soil apart.
-Neil Shea
PHOTO:PALHERMANSEN